Abstract: Methane migration and distribution in deep coal seam is closely related to the coupled process among thermal， gas flow and mechanical fields. Based on the THM (thermal hydraulic mechanical)coupling model， coal seam condition and in-situ test data， numerical simulation was conducted to examine the factors affecting the distribution of methane pressure and content. It is shown that， permeability of coal seam is the main factor affecting gas pressure distribution， where the effective stress coefficient， initial porosity， elastic modulus and adsorption swelling coefficient all have important impacts on permeability. Methane content distribution is controlled by both gas pressure and coal temperature. Methane content may be overestimated without considering the coal seam temperature.

Key words: methane distribution, deep coal seam, variable temperatures, THM(thermal hydraulic mechanical) coupling, numerical simulation